I have no experience with the others, but I've been less then happy with the prizm. The biggest problem I have is that I either set it a little low and it skims almost nothing, or I turn it up a little and it creates a very wet skimmate, tries to overflow the cup, and sends microbubbles into the tank. After 6 months I've given up on trying to find the sweet spot and have just left it low. Anyway, that's my experience. Anyone with an idea on how to fix these problems, let me know.